Mercedes driver Nico Rosberg has played down his advantage after he led the way during both practice sessions at the German Grand Prix on Friday.
Rosberg, who triumped at Hockenheim upon Formula 1's most recent visit in 2014, beat team-mate Lewis Hamilton on both occasions, with Ferrari's Sebastian Vettel over half a second back in third.
Rosberg is nonetheless wary that Mercedes' rivals could close the gap across the remainder of the weekend.
"A good start to the weekend," commented Rosberg on his pace.
"It's great to be back here in Hockenheim at this historic track.
"The tarmac is old, so the way the tyres work is completely different to in Hungary where the tarmac was new. Here it's much more snappy and more of a challenge.
"But in general our car was working well out there today.
"Saying that, in Hungary we were very quick on Friday but then on Saturday and Sunday everyone was very close.
"So, we are warned by that to not get over-excited on a Friday. It's a good start but we'll see more tomorrow."
Hamilton was told to be conservative into the first corner amid warnings over track limits, in order to avoid a third reprimand of the year, on a relatively low-key day at Hockenheim.
"We had a fairly straightforward two sessions today," he said.
"No real surprises and a good first step for the weekend. We'll see where we are in qualifying tomorrow."